prt10.1108/prtPigment & Resin Technology0369-9420Emerald Group Publishing Limited10.1108/prt.2005.12934bab.002e-non-articleSecondary articleMethodscat-ENGGEngineeringcat-MATSMaterials scienceFrom fashionwear to racing overalls – reliable and economical dyeing of high- quality fabrics made from cationic dyeable fibres01042005342© Emerald Group Publishing Limited2005Dyes,Colours technology.peer-reviewednoacademic-contentyesrightslinkexcludedFrom fashionwear to racing overalls – reliable and economical dyeing of high- quality fabrics made from cationic dyeable fibres

From fashionwear to racing overalls –reliable and economical dyeing of high- quality fabrics made from cationicdyeable fibres

Keywords:Dyes, Colours technology

Cationic dyeable fibres are frequently used in modern fibre blends,especially when a combination of brilliant shades and top fastness properties isrequired. However, dyeing multifunctional fabrics is very demanding. Theincreasing variety of fibre blends means dyers need a wide range of carefullymatched dyes as well as extensive knowledge of the properties of fibres and howto dye them. DyStar's restructured Astrazonw range makes it the market leader inthis field. The optimised product range is designed to help textile finishersmeet top quality requirements while minimising costs (Plate 1).

Plate 1The new Astrazon range offers a full range of shades for all types ofcationic dyeable fibres

Manmade fibres such as acrylics and other cationic dyeable fibres allowdesigners to create a wide variety of articles without having to worry aboutproblems like wear comfort. That is why they are popular for fashionableknitwear and functional sportswear as well as table linen, upholstery velvets,carpets, bathmats and even the fabrics used for cuddly toys and imitation fur.Alongside polyacrylonitrile (PAN) fibres, there is growing demand forspecialities such as modacrylic, cationic dyeable polyester and polyamide andm-aramid fibres. Modacrylic fibres are mainly used as flame retardant componentin household textiles and functional fabrics such as blankets in planes.Cationic dyeable polyester is frequently found in top-fashion sports andleisurewear, while blends of cationic dyeable polyamide with standard polyamideincrease the variety of shades that can be obtained on carpets using thedifferential dyeing method. Workwear made from m- aramid fibres such as Nomexwprotects fire-fighters in extreme conditions and fireproof overalls made of thesame material have long been indispensable in motor racing.

The properties of cationic dyeable synthetics are as multifarious as theirapplications. Evidently, such fibres are not easy to dye so textile finishersneed the necessary expertise. For example, for special processes such as dyeingPAN fibres during the wet spinning process high-quality liquid dyes that meetnarrow quality tolerances are essential. The impact of steam and heat duringproduction of the fibres places enormous demands on the Astrazon liquid dyes.However, the benefit is that the fibres can be dyed during the spinning process,thus reducing the dyeing process from hours to just seconds.

The new face of Astrazon

DyStar has restructured its broad offering of cationic dyes under the motto“The new face of Astrazon”. The restructured range is geared to thelatest fibre trends and reflects today's wide range of fibres and fibre blends,rapidly changing fashion trends and steadily rising expectations. New andoptimised dyes have been integrated to round out the range. All imaginableshades can now be created with Astrazon dyes: from specialities such asfluorescent yellow and red to popular black and navy blue hues.

There is no doubt that DyStar markets the world's widest and most balancedrange of cationic dyes. It can therefore offer solutions for all types ofcationic dyeable fibres. Unlike conventional Colour Index products, Astrazondyes meet consistently high quality standards, providing the basis for reliableand economical dyeing processes (Plate 2).

Plate 2In the world's only pilot gel dyeing facility, DyStar tests new liquid dyes,auxiliaries and fibres under operating conditions

Clear benefits for textile finishers

Innovations and cost savings are vital to withstand international competitionin the textile industry. As the world's premier supplier of textile dyes, DyStaroffers customers the benefits of maximum colour confidence and controlledcoloration through its Astrazon dyes.

Colour confidence means the products meet top standards of productionfastness and shade consistency throughout the production process and haveexcellent service properties. Besides having extremely high light and wetfastness, Astrazon dyes meet the high weather fastness specifications set foroutdoor articles. Other highlights are good solubility and low dusting, ensuringexcellent industrial hygiene. What is more, with Astrazon dyes conformance toall common ecological standards including Oeko Tex Standard 100 is no problem.

Controlled coloration ensures that dyeing and printing processes runsmoothly. Astrazon quality dyes enable experienced dyers to achieve “right-first-time” quotas of up to 98 percent because all Astrazon dyes are extremelywell- matched, allowing reliable dyeing even if process conditions fluctuate. Anadditional benefit is that dyeing processes can be optimised with the aid ofOptidye®, a computer software. That avoids faulty dyeings, reduces unitproduction costs and raises productivity.

Always a step ahead

DyStar is one of the few suppliers that invest in in-house research anddevelopment in the field of cationic dyes. At its headquarters in Frankfurt,Germany, it has the world's only pilot gel dyeing facility, which is used todevelop new liquid dyes and test and develop auxiliaries and fibres in simulatedoperating conditions. This has enabled DyStar to increase its leading edge incationic dyes in recent years. DyStar offers textile finishers an attractivepackage of optimised Astrazon dyes and extensive service. That is the key toreliable dyeing of modern fabrics, without closing the doors to innovation(Plate 3).

Plate 3Cationic dyeable fibres have gained ground in recent years and now have afirm place in modern fibre blends